The invention relates generally to machinery having implements and, more particularly to a swivel device for support wheels mounted for rotation between stops within a swivel angle, on mounted implements for machines. In particular the swivel device is useful for swath pick-up devices on forage harvesters and bale presses, but also other drawn or mounted implements such as cutterbars, turners, swathers, etc., wherein the support wheels which are connected by supporting arms to the side walls of the front attachment are used for support of the mounted implement on the ground and the support wheels can be swiveled into a position which increases the width of the mounted implement and into a position which decreases the width of the mounted implement.
Mounted implements have support wheels in order on the one hand to support the weight of the mounted implements at least partially on the ground and on the other hand to control movably arranged components of a mounted implement in such a way that the latter in its swivel position copies the ground contour. In this case the support wheels have a mounting for rotation about an essentially vertical axis, so that when travelling round bends the support wheels can adapt to the radius of curvature and do not grind over the ground. To keep the performance quiet and protect operation, the swivel angle is limited by stops to a sensible range, e.g. 45xc2x0, so that a support wheel can be pivoted to right and left from the straight-ahead position by 22.5xc2x0 each. For the possibility of picking up a wide crop swath or for achieving as wide as possible a working width of a mounted implement, the pick-up devices in general have a correspondingly wide width. With the support wheels additionally arranged in both side regions, the pick-up devices and mounted implements achieve a width which can be wider than the width of the remainder of the harvester. As this leads to obstruction on transport journeys in public road traffic or to exceeding the permitted vehicle width, various designs which reduce the width dimensions in the transport position are already known. But in other respects too the extra width from the laterally mounted support wheels can have an adverse effect, for example when maneuvering with the agricultural machine.
Thus for example there is known a front attachment for harvesters (DE 297 13 081 U1) whose support wheels in the transport position are swiveled by a manually triggered swivel movement by means of two or one double swivel bearing through initially 180xc2x0 into a position behind the front attachment, and then also raised to remove contact with the ground. Although with this design the support wheels in the transport position no longer project from the side wall of the front attachment, both the structural space requirements for this between the rear wall of the front attachment and the front wheels of the harvester, and the necessary expenditure on manual operation, are very high.
The design according to the invention allows the swivel pin to be held by at least two coupling levers in a position in which the support wheels can continue to run straight ahead in spite of the stops in both end positions. If the coupling levers are swiveled parallel to each other, the degrees of freedom between the two stops, between which the support wheel can turn, are preserved independently of the swivel position. If the coupling levers are attached to a swivel-mounted supporting arm, adjustment of height can be performed as well as lateral swiveling. If the coupling levers can be swiveled about non-vertically mounted swivel bearings, the swivel movement combines lateral displacement of the support wheels with a change of height. Due to hydraulic operation of the swivel device from the driver""s cab of the harvester, easy control becomes possible. In case of a combination of the non-vertically mounted swivel bearings with hydraulic operation, by extending the hydraulic cylinders the support wheels can be displaced from a low lateral swivel position to a higher one in front of the mounted implement. In each position between the maximum low lateral position and the maximum higher front position of the support wheels they can support the mounted implement, so that remote-controlled infinitely variable adaptation of the height of the implement is possible due to the arrangement according to the invention. In the transport position too, the support wheels which are swiveled forwards protect the implement from possible collisions with obstacles or from unevenness of the road. All the above advantages can be obtained with slight restrictions with manual operation as well. With a variously controllable extended position of the hydraulic cylinders in combination with non-vertically mounted swivel bearings, active swiveling of the implement supported by the support wheels, possibly regulated by an additional electronic control unit, can be obtained. As a result of the advantageous design of the swivel mechanism and the favorable arrangement of the support wheels, there are low space requirements overall.
In accordance with the present invention there is provided a swivel device for a support wheel of a mounted implement including means for mounting the support wheel for movement between a plurality of stops within a swivel angle. A plurality of supporting arms connect the support wheel to a side wall of the implement. The support wheel are pivotable between a position which increases the overall width of the mounted implement and a position which decreases the overall width of the mounted implement. A plurality of swivelable coupling levers are connected to a swivel pin, and the swivelable coupling levers are connected to a plurality of swivel bearings.